nfsd: Protect unconfirmed client creation using client_lock

...instead of relying on the client_mutex.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 4b42cb9..f149e30 100644 (file)
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -1923,7 +1923,7 @@ add_to_unconfirmed(struct nfs4_client *clp)
        add_clp_to_name_tree(clp, &nn->unconf_name_tree);
        idhashval = clientid_hashval(clp->cl_clientid.cl_id);
        list_add(&clp->cl_idhash, &nn->unconf_id_hashtbl[idhashval]);
-       renew_client(clp);
+       renew_client_locked(clp);
 }
 
 static void
@@ -1937,7 +1937,7 @@ move_to_confirmed(struct nfs4_client *clp)
        rb_erase(&clp->cl_namenode, &nn->unconf_name_tree);
        add_clp_to_name_tree(clp, &nn->conf_name_tree);
        set_bit(NFSD4_CLIENT_CONFIRMED, &clp->cl_flags);
-       renew_client(clp);
+       renew_client_locked(clp);
 }
 
 static struct nfs4_client *
@@ -1950,7 +1950,7 @@ find_client_in_id_table(struct list_head *tbl, clientid_t *clid, bool sessions)
                if (same_clid(&clp->cl_clientid, clid)) {
                        if ((bool)clp->cl_minorversion != sessions)
                                return NULL;
-                       renew_client(clp);
+                       renew_client_locked(clp);
                        return clp;
                }
        }
@@ -2152,7 +2152,8 @@ nfsd4_exchange_id(struct svc_rqst *rqstp,
                  struct nfsd4_compound_state *cstate,
                  struct nfsd4_exchange_id *exid)
 {
-       struct nfs4_client *unconf, *conf, *new;
+       struct nfs4_client *conf, *new;
+       struct nfs4_client *unconf = NULL;
        __be32 status;
        char                    addr_str[INET6_ADDRSTRLEN];
        nfs4_verifier           verf = exid->verifier;
@@ -2187,6 +2188,7 @@ nfsd4_exchange_id(struct svc_rqst *rqstp,
 
        /* Cases below refer to rfc 5661 section 18.35.4: */
        nfs4_lock_state();
+       spin_lock(&nn->client_lock);
        conf = find_confirmed_client_by_name(&exid->clname, nn);
        if (conf) {
                bool creds_match = same_creds(&conf->cl_cred, &rqstp->rq_cred);
@@ -2218,7 +2220,6 @@ nfsd4_exchange_id(struct svc_rqst *rqstp,
                                status = nfserr_clid_inuse;
                                goto out;
                        }
-                       expire_client(conf);
                        goto out_new;
                }
                if (verfs_match) { /* case 2 */
@@ -2226,6 +2227,7 @@ nfsd4_exchange_id(struct svc_rqst *rqstp,
                        goto out_copy;
                }
                /* case 5, client reboot */
+               conf = NULL;
                goto out_new;
        }
 
@@ -2236,17 +2238,18 @@ nfsd4_exchange_id(struct svc_rqst *rqstp,
 
        unconf  = find_unconfirmed_client_by_name(&exid->clname, nn);
        if (unconf) /* case 4, possible retry or client restart */
-               expire_client(unconf);
+               unhash_client_locked(unconf);
 
        /* case 1 (normal case) */
 out_new:
+       if (conf)
+               unhash_client_locked(conf);
        new->cl_minorversion = cstate->minorversion;
        new->cl_mach_cred = (exid->spa_how == SP4_MACH_CRED);
 
        gen_clid(new, nn);
        add_to_unconfirmed(new);
-       conf = new;
-       new = NULL;
+       swap(new, conf);
 out_copy:
        exid->clientid.cl_boot = conf->cl_clientid.cl_boot;
        exid->clientid.cl_id = conf->cl_clientid.cl_id;
@@ -2259,9 +2262,12 @@ out_copy:
        status = nfs_ok;
 
 out:
+       spin_unlock(&nn->client_lock);
        nfs4_unlock_state();
        if (new)
-               free_client(new);
+               expire_client(new);
+       if (unconf)
+               expire_client(unconf);
        return status;
 }
 
@@ -2900,7 +2906,8 @@ nfsd4_setclientid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 {
        struct xdr_netobj       clname = setclid->se_name;
        nfs4_verifier           clverifier = setclid->se_verf;
-       struct nfs4_client      *conf, *unconf, *new;
+       struct nfs4_client      *conf, *new;
+       struct nfs4_client      *unconf = NULL;
        __be32                  status;
        struct nfsd_net         *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
 
@@ -2909,6 +2916,7 @@ nfsd4_setclientid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
                return nfserr_jukebox;
        /* Cases below refer to rfc 3530 section 14.2.33: */
        nfs4_lock_state();
+       spin_lock(&nn->client_lock);
        conf = find_confirmed_client_by_name(&clname, nn);
        if (conf) {
                /* case 0: */
@@ -2926,7 +2934,7 @@ nfsd4_setclientid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
        }
        unconf = find_unconfirmed_client_by_name(&clname, nn);
        if (unconf)
-               expire_client(unconf);
+               unhash_client_locked(unconf);
        if (conf && same_verf(&conf->cl_verifier, &clverifier))
                /* case 1: probable callback update */
                copy_clid(new, conf);
@@ -2941,9 +2949,12 @@ nfsd4_setclientid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
        new = NULL;
        status = nfs_ok;
 out:
+       spin_unlock(&nn->client_lock);
        nfs4_unlock_state();
        if (new)
                free_client(new);
+       if (unconf)
+               expire_client(unconf);
        return status;
 }